You might want to look into getting a custom exhaust system. I did it mainly because I had to go up to a 2.5". The stock ITR exhaust has two resonators in addition to the muffler. If you put on a system with a straight through muffler and no resonators it will be considerably louder. I also wanted to remove the cat so I was looking at a big decible increase. What I did was replace the cat with a 18" glasspack muffler (some people call them resonators, but they are different). It only cost about $25. Then I had a custom system put together with two resonators just like the stock system except a full 2.5" all they way through. Even with a straight through magnaflow muffler it wasn't much louder then stock, but it flowed A LOT better. I shopped on the classifieds here and at honda-tech. I was lucky to find some of the parts used, so it didn't really cost me an outragous amount. I just used aluminized steel because I didn't care what something hanging under my car looked like, and it will last just as long. In fact I didn't want anything conspicuous. No big shiny muffler or tip for me, and not a lot of annoying buzz. Mandrel bent pipes are best, but I don't think crush bending really constricts flow that much.